1. Field of the Invention
The present invention concerns a method and an apparatus for synchronizing the operation of an x-ray system and a magnetic system, and in particular concerns such a method and apparatus wherein the x-ray system has a flat panel x-ray detector.
2. Description of the Prior Art
Various types of medical procedures are conducted using magnetic tracking systems, wherein a magnetic field is generated externally of a patient and an object in the patient is tracked, or its location identified, by detecting and analyzing voltages induced at one or more coils carried by the object, that arise due to the changing magnetic field. Such magnetic tracking is used, for example, in PCI (percutaneous coronary intervention) and cardiac EP (electrophysiology) interventions and examinations. Such magnetic tracking systems are able to track a catheter or a stent in such procedures and examinations.
X-ray systems are also used in such procedures. Until recently, most x-ray systems employed an x-ray image intensifier for the purpose of detecting x-rays attenuated by the patient, coupled to a CCD camera for the purpose of producing video images from the detected x-rays. Such detection/imaging systems are not influenced by the magnetic fields generated by magnetic tracking systems, and therefore such x-ray systems were compatible for use with magnetic tracking systems. Another type of radiation detector is a flat panel x-ray detector. Such flat panel x-ray detectors were primarily used in cathlab C-arm systems, however, in recent years their use has become widespread for all types of x-ray systems used for medical interventional purposes, including virtually universal use in EP labs. The use of flat panel x-ray detectors has become so widespread that they are close to becoming the standard type of x-ray detector that is used for all medical x-ray systems.
Such flat panel x-ray detectors, however, are susceptible to magnetic fields of the type generated by a magnetic tracking system or other types of devices that produce a magnetic field, such as ablation systems. Such magnetic fields can produce image artifacts in the images generated by flat panel x-ray detectors.